CLASSIFICATION OF THE BEES. 73 



Table of Genera. 



Both recurrent nervures received by the second cubital cell, or the second recur- 

 rent is interstitial with the second transverse cubitus. 

 Claws in 9 simple, neither cleft or without a subapical tooth, iu % cleft or 



simple ; face in % never marked with yellow or white 2. 



Claws in 9 cleft or with a distinct subapical tooth; in % cleft; face in % 

 anteriorly marked with yellow or white. 

 Face in % yellow or white; pygidium broadly emargiuate at apex, the 

 hypopygium trapezoidal broadly emargiuate: maxillary palpi 4-jointed; 

 body above clothed with fulvous hairs; the abdomen short. 



Trachusa Jariue = Diphysis Lepel. 

 Face in % with the clypeus anteriorly alone yellow ; pygidium triangular 

 entire, the hypopygium normal ; body clothed with whitish or cinere- 

 ous hairs, tinged with ochraceous on vertex and on thorax above, the 

 abdomen with distinct white fasciae. 



Zacesta Ashm. n. g. (Type Z. rnfipes Ashm.). 



2. Maxillary palpi 4- or 5-jointed 4. 



Maxillary palpi 3-jointed. 



Abdomen with the basal impression on the first abdominal segment not 

 bounded superiorly by a distinct transverse elevated line or carina. .3. 



Abdomen with the basal impression on the first segment bounded superiorly 

 by a distinct transverse elevated line or carina ; mandibles tridentate ; 

 claws simple; abdomen most frequently fasciate with white. 



Trypetes Schenck. 



3. Mandibles at apex tridentate; clypeus simple; triangular area of the meta- 



thorax smooth, shining; % antennae not crenulate beneath. 

 9 abdomen elongate, longer than the head and thorax united ; transverse 

 median nervure in front wings quite interstitial ; pygidium in % short, 

 impressed above, hut hroadly, squarely truncate posteriorly, with acute 

 angles; second ventral segment with a prominent tooth or ridge. 



Heriades Spinola. 

 9 abdomen broader and shorter, not longer than the head and thorax 

 united, usually somewhat shorter; transverse median nervine in front 

 wings not quite interstitial with the basal nervure, uniting with the 

 median vein a little before the origin of the basal nervure: pygidium 

 in %> 4-dentate; second ventral segment normal. 



Ashmeadiella Ckll. 

 Mandibles at apex hidentate: clypeus in 9 with a lamina, tubercle or ridge 

 anteriorly; triangular area of metathorax opaque, crenulate basally ; 

 % antenna? crenulate beneath, the pygidium deeply emarginate, hiden- 

 tate or forked. . Chelostoma Latr. = Gyrodroma Klug (Thorns.) = 

 Chelynia Prov. 

 1 Maxillary palpi 5-jointed; flagellum in both sexes compressed : abdomen in % 

 elongate, usually with the segments narrowly fasciate. the impression 

 at base of first segment not broad, poorly defined, usually represented 



by a longitudinal sulcus .",. 



Maxillary palpi 4-jointed ; abdomen most frequently shorter, not elongate, the 

 first dorsal segment with a broad, subcoocave impression at base, 

 rarely otherwise. 



TKANS. AM. ENT. SOC. XXVI. (10) JUNE. 1899. 



